Drift eliminator

ABSTRACT

A drift eliminator to prevent airborne water droplets which are generated in a cooling tower from escaping through the discharge outlet by trapping the water droplets in the exhaust air and redirecting the air flow through the drift eliminator. The eliminator blades, hollow in cross-section, include three plane surfaces which incorporate a series of protrusions or sharp ridges for trapping water droplets which impinge on the eliminator blades and prevent same from becoming re-entrained in the air. The blades are formed with a ballistic nose of an air foil type leading edge to reduce resistance to air movement across the drift eliminator. The drift eliminator blades are assembled into unique panels to reduce field assembly time.

United States Patent [1 1 Furlong et a1.

[ 1 July 31, 1973 DRIFT ELIMINATOR [75] Inventors: Donn B. Furlong, SanRafael; John C. Ovard, Santa Rosa, both of Calif.

[73] Assignee: Fluor Cooling Products Company [22] Filed: July 9, 1971[21] Appl. No.: 161,029

[56] References Cited UNITED STATES PATENTS 1,974,768 9/1934 Daniels eta1. 55/444 X 2,228,484 1/1941 Ramsaur et a1..... 55/257 X 2,356,1928/1944 Yingling 55/443 X 2,643,736 6/1953 Smith 55/440 2,674,849 4/1954Bowden 55/444 X 2,854,090 9/1958 Sl0ugh..... 261/DIG. 11 3,116,989l/l964 Warren 55/257 3,527,030 9/1970 Hungate... 55/440 2,972,358 2/1961Hinden 98/121 X 1,047,765 12/1912 Derby 55/257 1,134,976 4/1915 Braemeret al. 55/257 X 2,247,514 7/1941 Mart 26l/D1G. 11 2,400,623 5/1946 Bairdet al. 55/440 2,741,973 4/1956 Swor 160/223 X 2,892,509 6/1959 Baker eta1. 261/DIG. 11 3,372,530 3/1968 Zimmer 55/444 X 1,974,768 9/1934Daniels et al. 55/444 X FOREIGN PATENTS OR APPLICATIONS 644,686 10/1950Great Britain 55/257 1,187,230 4/1967 Great Britain 98/121 508,326l/l952 Belgium 26l/DIG. 11 1,051,600 9/1953 France 55/257 1,288,2352/1962 France 465,955 10/1951 Italy 55/DIG. 37

OTHER PUBLICATIONS German Printed Application No. 1,196,128, printedJuly 8, 1965 (3 sheets drawing, 3 pages spec.)

Soplasco Eliminator Blades, Southern Plastics Company, 408 PendletonSt., Columbia, SC, 4 pages, received in the Patent Office Sept. 24,1965.

Swirlaway, Labconco Corporation, 8811 Prospect, Kansas City, Missouri64132, 4 pages, received in the Patent Office Oct. 17, 1968.

Primary Examiner-Dennis E. Talbert, Jr. Attorney-Charles M. Kaplan andJoel E. Siegel [57] ABSTRACT A drift eliminator to prevent airbornewater droplets which are generated in a cooling tower from escapingthrough the discharge outlet by trapping the water droplets in theexhaust air and redirecting the air flow through the drift eliminator.The eliminator blades, hollow in cross-section, include three planesurfaces which incorporate a series of protrusions or sharp ridges fortrapping water droplets which impinge on the eliminator blades andprevent same from becoming reentrained in the air. The blades are formedwith a ballistic nose of an air foil type leading edge to reduceresistance to air movement across the drift eliminator. The drifteliminator blades are assembled into unique panels to reduce fieldassembly time.

PAIENIED I975 3.748.832

sum 2 OF 2 INVENTORS DON/V B. FURLO/VG JOHN C. OVARD BY TTORN DRIFTELIMINATOR BACKGROUND OF THE INVENTION This invention relates to drifteliminators for eliminating entrained droplets of liquid from agenerally upward flow of gas, and more particularly to a novel drifteliminator assembly as is used primarily in mechanical draft or naturaldraft water cooling towers for removing water entrained in air as itflows upward through the tower.

In cooling towers wherein water is cooled as a consequence of themovement of air therethrough, a substantial amount of the water iscarried from the tower by the air unless means is provided within thepath of travel of the air to eliminate the water and redirect the samedownwardly to the intended point of collection within a sump underlyingthe fill assembly. Reference may be had to US. Pat. No. 2,892,509,assigned to the same assignee as the present invention, for anunderstanding of the conventional types of water cooling towers(crossflow and counterflow) to which the instant invention relates andthe nature and disposition of drift eliminators commonly employedtherein. In some installations the actual loss of water in this mannerrepresents a serious difficulty due to the scarcity of water and thedifficulty of obtaining the same, and in other installations thepresence of the excessive moisture carried out by the stream of air maycause considerable inconvenience and damage to property in the immediatevicinity and in the path of the stream of air.

Heretofore known drift eliminators, of the type employed in coolingtowers, have sacrificed cooling tower efficiency in order to effectivelyremove entrained water. These eliminators include eliminator bladeshaving sharp leading edges which causes a relatively high resistance toflow of air therethrough, which results in reduced air velocitiesthrough the tower and consequently a reduced capacity of the towerinstallation of a given size. The drift eliminator of the presentinvention has a lower resistance to flow of air per unit of area andthus a minimum pressure drop in the air stream which results in anincrease in air capacity of the tower without requiring installation ofa large fan and motor. It is known to provide drift eliminators whichinclude blades which define passageways inclined in opposite directions.However, the water which collects on the surfaces of these blades tendsto tear off these surfaces and again become entrained in the air at thepoints where the passages change direction. The drift eliminator of thepresent invention includes means to retain the water on the surfaces ofthe eliminator blades. Prior art cooling tower drift eliminators havefurther required extensive field erection which has increased theerection time and cost of the tower. The drift eliminator assembly ofthe present invention may be factory assembled into panels which requireminimum field erection time and cost.

SUMMARY OF THE INVENTION It is a primary object of the present inventionto provide a drift eliminator having a low resistance to air movementacross the drift eliminator blades.

Another object is to provide a drift eliminator for gas and liquidcontact apparatus, such as cooling towers, which has improved efficiencyin precluding loss of water from the housing through the air dischargeoutlet with a minimum of pressure drop in the air stream and withoutsubstantially interfering with the flow of air through the fill area.

A further object is to provide a drift eliminator of the type used incooling towers which induces more complete deposition of the waterdroplets in the air and thus permits higher air velocity through thetower with out an increase in escaped water particles through the towerdischarge outlet.

A still further object of the present invention is to provide a drifteliminator assembly for use in a cooling tower which is compact and maybe constructed in factory assembled panels to reduce the field erectiontime, and which may be easily placed in or removed from operativeposition for repair or other purposes.

Another object is to provide a drift eliminator having theaforedescribed features which is resistant to chemicals found in thewater to be cooled, possesses durability and long life, is resistant toalgae and fungus organisms, possesses sufficient strength and stiffness,and is easy and inexpensive to manufacture and assemble.

The drift eliminator of the present invention prevents airborne waterdroplets which are generated in the cooling tower from escaping throughthe discharge outlet by trapping the water droplets in the high velocityexhaust air from the tower fill area and redirecting the air flowthrough the drift eliminator. Entrained water droplets impinge on thedrift eliminator blades and drain down through the tower to the coldwater collecting basin. The eliminator blades, hollow in crosssection,include three plane surfaces which incorporate a series of protrusionsor sharp ridges for trapping water droplets which impinge on theeliminator blades and prevent same from becoming re-entrained in theair. The blades are formed with a ballistic nose of an air foil typeleading edge to reduce resistance to air movement across the drifteliminator. The drift eliminator blades are assembled into unique panelsto reduce field assembly time.

DESCRIPTION OF THE DRAWINGS Other objects and features of the inventionwill become apparent to those skilled in the art as the disclosure ismade in the following description of a preferred embodiment of theinvention, as illustrated in the accompanying sheets of drawings, inwhich:

FIG. 1 is a vertical section taken through a representative crossflowcooling tower incorporating the drift eliminator of the presentinvention;

FIG. 2 is a front elevational view of a drift eliminator panelincorporating eliminator blades of the present invention;

FIG. 3 is a side elevational view of a drift eliminator panelincorporating eliminator blades of the present invention;

FIG. 4 is a perspective view of a portion of an eliminator blade of thetype shown in FIGS. 2 and 3;

FIG. 5 is an enlarged elevational view of a portion of the eliminatorblade in FIG. 4 illustrating the water entrapping projectionsincorporated at specific locations on the blade;

FIG. 6 is a sectional view of a portion of the drift eliminator assemblyadjacent the blade end illustrating the attachment of the eliminatorblade to a support angle member; and

FIG. 7 is a sectional view taken along line 77 of FIG. 6.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIG. 1, a crossfiowcooling tower is shown as having a housing 11 incorporating a top 12defining a water distributing pan 13. Liquid such as water to be cooledis pumped into the pan through inlet pipe 18 from which the liquiddrains via suitable metering outlets 15. After descending through thefill or packing section 16, the liquid is collected in cold watercollecting basin 17 for removal. Reference is made to U. S. Pat. No.3,468,52l assigned to the same assignee as the present invention, for acomplete disclosure of a preferred type of splash directing fillutilized in cooling tower fill sections.

A fan 19, rotated in stack 20 by drive 21, draws air laterally throughthe tower for upward discharge via the stack. The air passessuccessively through inlet openings between housing side wall inletlouvers 23, the fill 16 and through drift eliminators 24 as indicated byarrows 125.

As the water falls by gravity through fill section 16 it is broken upinto droplets by splashing on the fill, and also forms a water film onthe fill and structure parts. Cooling is accomplished essentially byevaporation from the surface of the droplets and films, and by sensibleheat transfer from water surfaces to the circulating air. During thisprocess, a certain number of water droplets will become entrained in theair stream. These entrained water droplets create a nuisance andpotential hazard if they are allowed to escape through the fan stack tothe outside air. Drift eliminators 24, in accordance with the presentinvention, prevent these airborne water particles, which are generatedin the cooling tower, from escaping through the fan stack 20. This isaccomplished by trapping the water particles in the high velocityexhaust air, from the cooling tower fill section 16, by redirecting theair flow as it passes through the drift eliminator 24. Entrained waterdroplets impinge and collect on the drift eliminator blades and draindown through the tower to the basin 17.

Drift eliminator assembly 24 is of special construction differingsubstantially from those heretofore employed in this field for thepurpose of more effectively and efficiently removing the water dropletsentrained in the air stream and controlling the direction of air fiow soas to minimize the pressure drop in the air stream. To accomplish theseresults and the previously mentioned objectives the drift eliminatorassembly 24 includes a plurality of eliminator panels 26 which haveeliminator blades 28 supported therein. Although drift eliminatorassembly 24 will be described in detail in conjunction with a crossfiowcooling tower it should be understood that eliminator assembly 24 isalso intended for use in counterflow cooling towers.

As best seen in FIG. 4, eliminator blade 28 is an elongated cellularmember of substantially V-shape hollow cross-section including a pair ofinclined first and second sections 30 and 32, respectively, having equalbut opposite slopes, which are connected together at their convergingends by a third section 34. The diverging ends of sections 30 and 32have nose sections 36 and 38 integral therewith, which are substantiallyparallel to section 34. The outer edges of nose sections 36 and 38 areformed of an air foil-type leading edge to reduce resistance to airmovement across eliminator blade 28. Stiffener members 39, 40, 41 and 42define the ends of sections 30, 32, 34, 36 and 38 and serve to increasethe rigidity of blade 28. Blade 28 is preferably extruded of a plasticmaterial such as polypropylene or polyvinylchloride because of theirresistance to chemicals found in cooling of process water streams,durability and long life, resistance to algae and fungus organisms, andability to provide the needed strength and stiffeness.

Eliminator blades 28 have a plurality of rigid longitudnally extendingprojections 45 formed on the outer and inner surfaces of sections 30 and32 for trapping and retaining the water droplets which impinge on thesurfaces blades 28. Projections 45 are preferably substantially squarein cross-section, as best seen in FIG. 5, and are approximately 0.02inches on each side. The size and number of projections 45 may varyaccording to the spacing of blades 28, the air flow rate through theeliminator assembly, and the degree of water elimination required. Aseries of projections 45 are provided at the outer portions of the innersurfaces of sections 30 and 32 and at the inner portions of the outersurfaces of sections 30 and 32 for reasons which will hereinafter becomemore apparent.

As best seen in FIGS. 1-3, eliminator blades 28 are supported between apair of angle support members and 52 in a spaced and facially opposedrelationship to one another so as to define a plurality passageways 55,allowing the passage of air therethrough. Each passageway 55 includes anentry passage 57 formed by the facing sections 30 of adjacent blades 28,a short connecting passage 58 formed by the facing sections 34 ofadjacent blades 28, and an exit passage 60 formed by the facing sections32 of adjacent blades 28. Passages 57 are inclined to the path of travelof the water droplet entrained air to permit direct impingement of theair against the surfaces thereof. Passages 60 are inclined in theopposite direction to passages 57 such that the air passing throughpassages 57 and 58 will impinge against the surfaces of passage 60.Blades 28, and consequently passageways 55, are preferablylongitudinally inclined about l0 so as to cause the water collected onthe blade surface to fiow towards the ends of the blades and then dropthrough the tower to the collecting basin 17.

As best seen in FIGS. 3, 6, and 7, blades 28 are secured to supportmembers 50 and 52 to form panels 26 in a unique manner which securelypositions blades 28 in a way which permits water collected on the bladesurfaces to pass through support members 50 and 52 and flow down theirouter surfaces to collecting basin 17. Support members 50 and 52 eachhave a first series of spaced openings 62 longitudinally extendingadjacent the entry edge thereof and a second series of spaced openings62 longitudinally extending adjacent the other edge thereof. Pins extendthrough openings 62 and 64 and securely grasp the ends of blades 28.Pins 65 include a head portion 66 and a stem portion 67. Stem portion 67is preferably of non-circular crosssection, i.e., a diamond shape.Openings 62 are similarly shaped to receive stem 67 and prevent rotationtherein. A longitudinally extending slot 68 is cut out of stem 67 so asto define a pair of finger members 69 and 70 which grasp and hold blades28 in a fixed position. The outer ends of members 69 and 70 may bebevelled to facilitate engagement of blades 28. Slot 68 is preferablydimensioned slightly less than the thickness of stiffener members 39 and41 such that as pin 65 passes through opening 62 and 64 and is forcedagainst stiffener members 39 and 41, the fingers 69 and 70 securelyreceive members 39 and 41 therebetween. Pins 50 may, in addition, besolvent welded at the contact surfaces between stem 67 and members 39and 41 and at the contact surfaces between head 66 and members 50 and52. Openings 62 and 64 are positioned on member 50 and 62 such that whenstiffener members 39 and 41 are in respective alignment with openings 62and 64 section 30 of blade 28 is approximately inclined 45 to thedirection of air flow. Openings 64 are dimensioned and shaped such thathead 66 will not pass therethrough and will not completely cover opening64 so as to permit water from the surfaces of blades 28 to pass througha portion of opening 64. As seen in FIG. 3 and 6, openings 64 areangular cut-outs which are dimensioned to receive stem 67 through aportion thereof, prevent head 66 from passing therethrough, and stillleave a portion not covered by head 66 to permit water collected onblades 28 to pass therethrough.

Panels 26 are secured to the tower structural supports in a conventionalmanner such that they are positioned inboard of fill section 16 and in afacially opposed relationship to inlet louvers 23. Panels 26 arepreferably longitudinally inclined approximately so as to cause waterformed on the surfaces of blades 28 to flow towards the respective endsthereof.

In the operation of the tower, water to be cooled is supplied throughinlet pipe 18 into pan l3 and distributing over fill section 16 viametering outlets 15. The water then falls by gravity through fillsection 16 where it is broken up into droplets by splashing on the fill,and also forms a water film on the fill and structure parts. Air isdrawn into the tower through inlet louvers 23 and then through fillsection 16 by fan 19. The gravitating water is effectively cooled by thedraft of air passing through fill section 16 and is collected in coldwater basin 17 Cooling is accomplished essentially by evaporation fromthe surface of the droplets and films and by sensible heat transfer fromwater surfaces to the circulating air. During the process, a certainnumber of water droplets become entrained in the air stream and create anuisance and potential hazard if they are allowed to escape through thefan stack 20 to the outside air.

The air with the water droplets entrained therein flows from fillsection 16 through drift eliminators 24, as indicated by arrows 125 inFIG. 1, and out fan stack 20. The water entrained air enters passages 57of eliminators 24 changing its direction of flow from substantiallyhorizontal to an inclined direction as it contacts the lower surfaces ofpassages 57. The force of the air stream on the entrained droplets issufficient to cause most of the droplets to gravitate towards the lowersurface of passage 57 and collect thereon' The water so collected tendsto migrate and build-up towards the upper end of the lower surfaces ofpassages 57. Projections 45, positioned at said upper end, substantiallyprevent the water from tearing off the lower surfaces of passages 57 andbecoming re-entrained in the air as the stream leaves passage 57 andenters passages 58. The finer droplets, and any heavy ones which mayelude elimination in passages 57, are carried by the air stream throughpassages 58 into passages 60 where it changes direction again uponcontact with the upper surface of passages 60. The droplets entrained inthe air, being heavier than air, are thrown against the upper surface ofpassages 60 by centrifugal action and tend to migrate to the outer endthereof. Projections 45, positioned at said outer end, substantiallyprevent the water from tearing off the outer end of the upper surfacesof passages 60 and becoming re-entrained in the air as it leavespassages 60 to be drawn out through fan stack 20.

As heretofore mentioned, blades 28 and consequently passages 57 and 60are longitudinally inclined approximately 10. This causes the watercollected on the surfaces of passages 57 and 60 to flow downward towardssupport members 50 and 52 and then through openings 64. The water isthen free to gravitate down the outer surfaces of support members 50 and52 to be collected in basin 17.

The drift eliminator 24 of the present invention provides more completedeposition of water droplets entrained in the air than prior arteliminators and reduces the amount of water collected on the eliminatorblades 28 that becomes re-entrained in the air as the air stream passesthrough the drift eliminator. Further resistance to air movement acrossdrift eliminator is reduced because of ballistic nose 36 provided at theleading edge of blades 28. The unique construction of eliminator panels26 permits water collected on blades 28 to pass therethrough and rundown the sides thereof, and permits panels 26 to be factory assembled soas to reduce on-site construction cost.

Although described with respect to a cross-flow cooling tower it iscontemplated that drift eliminator 24 may be equally as advantageouslyused in conjunction with a counterflow cooling tower. Those skilled inthe art will appreciate that by merely horizontally disposing panels 26below the stack of a conventional counterflow cooling tower theaforedescribed advantages are equally obtainable.

While the embodiment described herein is at present considered to bepreferred, it will be understood that various modifications andimprovements may be made therein, and it is intended to cover in theappended claims all such modifications and improvements as fall withinthe true spirit and scope of the invention.

We claim:

1. In combination with a water cooling tower having an air inlet, an airoutlet and means for directing currents of air along a path of travelfrom said inlet to said outlet in substantially horizontal, intersectingrelationship to water gravitating within the tower, a drift eliminatorwithin the tower, disposed to remove droplets of water entrained in saidair immediately prior to discharge of said air through said outlet; saiddrift eliminator including a plurality of eliminator panels comprising:

a. a plurality of longitudinally extending eliminator blades supportedat their respective ends by a pair of support members, said supportmembers having a plurality of openings passing therethrough;

. said eliminator blades being of a cellular structure havinglongitudinally extending stiffening members dividing said blades into aplurality of sections; and

. pin means for securing said eliminator blades to said support members,said pin means having a head portion and a shank portion, said shankportion passing through said opening in said support member and graspingsaid blade stiffening member, said head portion being dimensioned toprevent passage of it through said support member opening;

(1. at least some of said openings passing through said support membersbeing dimensioned and shaped to prevent said head portion from passingtherethrough and also to permit water collected on said blades to flowtherethrough.

2. The invention of claim 1 wherein said shank portion includes alongitudinally extending slot which receives said blade stiffeningmember.

3. The invention of claim 2 wherein said slot is dimensioned slightlyless than the thickness of said blade stiffening member such that saidshank portion securely grasps said stiffening member as it is forcedinto said slot.

4. The invention of claim 3 wherein each end of each eliminator blade issecured to said support member in at least two locations.

5. The invention of claim 1 wherein said eliminator blades arelongitudinally inclined to cause said water collected on said blades toflow through said openings in said support members.

6. The invention of claim 1 wherein the edges of said eliminator bladeswhich make first contact with said water droplet entrained air areformed with a ballistic nose of an air foil type leading edge to reduceresistance to air movement across said drift eliminator.

7. The invention of claim 1 wherein said eliminator blades areintegrally formed of a plastic material.

8. The invention of claim 1 wherein said eliminator blades areintegrally formed of polypropylene material.

9. The invention of claim 1 wherein said eliminator blades areintegrally formed of polyvinyl-chloride material.

10. In combination with a water cooling tower having an air inlet, anair outlet and means for directing currents of air along a path oftravel from said inlet to said outlet in substantially horizontal,intersecting relationship to water gravitating within the tower, a drifteliminator within the tower, disposed to remove droplets of waterentrained in said air immediately prior to discharge of said air throughsaid outlet; said drift eliminator including a plurality of eliminatorpanels comprismg:

a. a plurality of longitudinally extending eliminator blades supportedat their respective ends by a pair of support members, said supportmembers having a plurality of openings passing therethrough;

b. said eliminator blades being of a cellular structure havinglongitudinally extending stiffening members dividing said blades into aplurality of sections; and

c. pin means for securing said eliminator blades to said supportmembers, said pin means having a head portion and a shank portion, saidshank portion passing through said opening in said support member andgrasping said blade stiffening memher, said head portion beingdimensioned to prevent passage of it through said support memberopening;

(1. each of said eliminator blades being formed of first and secondinclined sections having opposite slopes which are secured together attheir converging ends by a third section of lesser width than said firstand second sections, the end of said first section which makes firstcontact with said water droplet entrained air includes a ballistic nosesection of an air foil-type leading edge attached thereto, saidstiffening members defining the respective ends of said first, secondand third sections.

11. The invention of claim 10 wherein each end of each eliminator bladesis secured to said supporting member by a pair of said pin meanspositioned to grasp the stiffener members associated with the ends ofsaid first and second section which make first contact with said waterdroplet entrained air.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. '3 748832 Dated July 3 1973 Inventor(s) Donn B Furlong, John C Ovard It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

In column.2, line 65 delete "77" and insert 7-7--.

On the cover page, the assignee should read Ecodyne Corporation.

(SE/NJ) Attcst:

Attesti'ng Officer Acting: Cmuiuissioncr of Patents

1. In combination with a water cooling tower having an air inlet, an airoutlet and means for directing currents of air along a path of travelfrom said inlet to said outlet in substantially horizontal, intersectingrelationship to water gravitating within the tower, a drift eliminatorwithin the tower, disposed to remove droplets of water entrained in saidair immediately prior to discharge of said air through said outlet; saiddrift eliminator including a plurality of eliminator panels comprising:a. a plurality of longitudinally extending eliminator blades supportedat their respective ends by a pair of support members, said supportmembers having a plurality of openings passing therethrough; b. saideliminator blades being of a cellular structure having longitudinallyextending stiffening members dividing said blades into a plurality ofsections; and c. pin means for securing said eliminator blades to saidsupport members, said pin means having a head portion and a shankportion, said shank portion passing through said opening in said supportmember and grasping said blade stiffening member, said head portionbeing dimensioned to prevent passage of it through said support memberopening; d. at least some of said openings passing through said supportmembers being dimensioned and shaped to prevent said head portion frompassing therethrough and also to permit water collected on said bladesto flow therethrough.
 2. The invention of claim 1 wherein said shankportion includes a longitudinally extending slot which receives saidblade stiffening member.
 3. The invention of claim 2 wherein said slotis dimensioned slightly less than the thickness of said blade stiffeningmember such that said shank portion securely grasps said stiffeningmember as it is forced into said slot.
 4. The invention of claim 3wherein each end of each eliminator blade is secured to said supportmember in at least two locations.
 5. The invention of claim 1 whereinsaid eliminator blades are longitudinally inclined to cause said watercollected on said blades to flow through said openings in said supportmembers.
 6. The invention of claim 1 wherein the edges of saideliminator blades which make first contact with said water dropletentrained air are formed with a ballistic nose of an air foil typeleading edge to reduce resistance to air movement across said drifteliminator.
 7. The invention of claim 1 wherein said eliminator bladesare integrally formed of a plastic material.
 8. The invention of claim 1wherein said eliminator blades are integrally formed of polypropylenematerial.
 9. The invention of claim 1 wherein said eliminator blades areintegrally formed of polyvinyl-chloride material.
 10. In combinationwith a water cooling tower having an air inlet, an air outlet and meansfor directing currents of air along a path of travel from said inlet tosaid outlet in substantially horizontal, intersecting relationship towater gravitating within the tower, a drift eliminator within the tower,disposed to remove droplets of water entrained in said air immediatelyprior to discharge of said air through said outlet; said drifteliminator including a plurality of eliminator panels comprising: a. aplurality of longitudinally extending eliminator blades supported attheir respective ends by a pair of support members, said support membershaving a plurality of openings passing therethrough; b. said eliminatorblades being of a cellular structure having longitudinally extendingstiffening members dividing said blades into a plurality of sections;and c. pin means for securing said eliminator blades to said supportmembers, said pin means having a head portion and a shank portion, saidshank portion passing through said opening in said support member andgrasping said blade stiffening member, said head portion beingdimensioned to prevent passage of it through said support memberopening; d. each of said eliminator blades being formed of first andsecond inclined sections having opposite slopes which are securedtogether at their converging ends by a third section of lesser widththan said first and second sections, the end of said first section whichmakes first contact with said water droplet entrained air includes aballistic nose section of an air foil-type leading edge attachedthereto, said stiffening members defining the respective ends of saidfirst, second and third sections.
 11. The invention of claim 10 whereineach end of each eliminator blades is secured to said supporting memberby a pair of said pin means positioned to grasp the stiffener membersassociated with the ends of said first and second section which makefirst contact with said water droplet entrained air.